1. Field of the Invention
The invention relates to trailers with a tongue with an attached wheel. In one aspect, the invention relates to a motorized wheel assembly for such trailers.
2. Description of the Related Art
Recreational watercraft, off-road vehicles, and similar pleasure craft are frequently transported by trailers towed behind an automobile, pickup truck, or similar vehicle. The trailer will typically a have a tongue which engages a ball hitch on the towing vehicle. When the trailer is being stored, the tongue of the trailer is frequently supported on a wheeled jack which is adjustable by means of the jack to maintain the trailer in a generally horizontal position. The wheel also enables the trailer to be moved without rehitching the trailer to the towing vehicle.
The trailer is typically moved by pushing the trailer by hand. However, trailers which are heavily loaded may be difficult to move by hand, particularly on a surface that is uneven or somewhat inclined, such as a driveway or pavement having construction joints. Furthermore, once the trailer begins moving, it may be difficult to control its movement or to position the trailer in the desired location. Consequently, the towing vehicle must frequently be used to move the trailer, which necessarily prevents the vehicle from being used for its primary purposes. As well, the towing vehicle may not be conveniently available when it is necessary to move the trailer. Space limitations may also make it difficult to move the trailer as desired using the towing vehicle.
One such prior art solution to this problem of moving the trailer is to motorize the wheel on the jack. For example, U.S. Pat. No. 3,861,482 to Stephens et al discloses a wheel assembly for attaching to a tongue of a trailer with an electric motor for driving the wheel. The motor is suspended on a wheel support bracket and drives the wheel through a gear reduction connecting the motor output shaft to the wheel axle.
As another example, U.S. Pat. No. 3,783,960 to Feliz discloses a motorized drive assembly for a trailer tongue wheel. The wheel is connected to an electric motor through a gear reducer and a sprocket and chain drive between the output shaft of the reducer and the wheel axle. The controls for the drive assembly are mounted in a switch box at the end of an extension cord.
The prior art motor assemblies are typically connected directly to the wheel axle, thus complicating removal of the wheel for replacement of the tire or other maintenance and repair. Furthermore, the drive assembly may utilize an internal combustion motor, which is loud and produces a noxious exhaust which is unacceptable for use in small or confined areas. Finally, some drive assemblies utilize intervening drive mechanisms between the motor and the wheel, such as a combination gear reducer and chain drive comprising multiple parts, which requires additional maintenance, and is complicated and costly to manufacture.